Service personnel such as technicians typically install, maintain and service equipment at customer sites that may be dispersed over a large geographic area. While on the customer's premises, mobile personnel may need access to a variety of data and systems located elsewhere and may be able to use portable computers such as laptop computers, to remotely access the required databases and systems via wireless and landline networks. In addition to accessing remote databases and systems, mobile personnel need to be able to receive and respond to communications sent by supervisors, and/or others, such as dispatchers and other controllers. One device available to deliver this type of interactive messaging service is an interactive pager. However, use of an interactive pager requires the purchase of a paging device (typically in the range of $500.00) plus monthly usage fees (typically in the range of $50.00). Since mobile personnel for some companies, such as some telecommunications companies, may number in the tens of thousands, and typically are already equipped with costly laptop computers, it would be helpful if the interactive messaging function could be performed using the laptop computer, thus saving the cost of the additional paging device and associated monthly usage fee. However, because mobile personnel with such a laptop computer already maintain contact with remote systems, the instant messaging function referred to above, must run concurrently with the remote accessing function.